Many types of printers include a roll of material that is used in the printing process. A typical example includes a roll of printing paper, upon which information may be printed. The paper is wound in a continuous sheet on a supporting core, and the core is mounted on a spindle in the printer. In another example, thermal printers utilize thermal transfer ribbon wound on a core. The thermal transfer ribbon is thermally activated during printing.
When the printing paper or ribbon is depleted, the empty core is removed from the spindle and replaced with a fully wound core, thereby returning the printer to service. The core typically includes features for accurately retaining the core on the spindle, in proper axial alignment with the printing mechanism, and in proper circumferential alignment around the spindle. Known printers that utilize cores retained on a spindle are referred to in U.S. Pat. Nos. 5,833,377; 5,947,618; 6,425,551; 6,609,677; and 6,609,678, and U.S. Patent Application Nos. 2003/0080238 and 2003/0106957, the entire disclosures of which are incorporated herein by reference.
Typically, each core with the attached ribbon is mounted on a corresponding spindle (also called “hub”). The spindle is generally cylindrical in shape and attached to a motor-operated assembly that accurately controls the rotation of the core and ribbon. Since the printer ribbons are required to be replaced, most printers that use ribbons mounted on cores must be designed such that the core containing the ribbon can be easily replaced. Accordingly, the design of the core/hub assembly must be such that aligning and inserting the core on the spindle and securing the core to the spindle are easily performed. Additionally, the interface between the spindle and a mounted core should be firm enough to keep the core with the associated ribbon attached and accurately controlled during operation of the printer. Further, the core must be desirably locked in axial position over the corresponding spindle to prevent unintended liberation or misalignment. These features increase the complexity of the core and spindle assembly, and correspondingly increase the cost. Cost is a significant factor in the manufacture and use of printer rolls, and must be minimized to maintain competitive advantage in the market of supplying replacement printing rolls.
Accordingly, it is desired to provide a simple, effective, low-cost versatile core for receiving wound sheet rolls and having corresponding retention features for mounting to various supporting spindles. The versatile core has a configuration that allows the core to accept and engage various configurations of spindle assemblies.